From: Chander Ganesan <chander@otg-nc.com>
To: Magnus Hagander <magnus@hagander.net>
Cc: Simon Riggs <simon@2ndquadrant.com>
Cc: Phillip Smith <phillip.smith@weatherbeeta.com.au>
Cc: Dominic Carlucci <carlucci@cae.com>
Cc: pgsql-general@postgresql.org
Cc: pgsql-admin@postgresql.org
Cc: carlucci@cae.ca
Subject: Re: [GENERAL] Backup
Date: Thu, 31 Jan 2008 10:02:14 -0500
Message-ID: <47A1E2F6.7060108@otg-nc.com> (raw)
In-Reply-To: <20080131144314.GH11977@svr2.hagander.net>
References: <00a201c85ee9$fbd1ca00$9b0014ac@wbaus090>
<1201252875.4257.387.camel@ebony.site>
<47A1BD51.3030902@otg-nc.com>
<1201786128.4453.287.camel@ebony.site>
<20080131143405.GC21660@svana.org>
<20080131144314.GH11977@svr2.hagander.net>
Magnus Hagander wrote:
> On Thu, Jan 31, 2008 at 03:34:05PM +0100, Martijn van Oosterhout wrote:
>
>> On Thu, Jan 31, 2008 at 01:28:48PM +0000, Simon Riggs wrote:
>>
>>> That sentence has no place in any discussion about "backup" because the
>>> risk is not just a few transactions, it is a corrupt and inconsistent
>>> database from which both old and new data would be inaccessible.
>>>
>> Hmm? I thought the whole point of a filesystem snapshot was that it's
>> the same as if the system crashed. And I was fairly sure we could
>> recover from that...
>>
>
> That was my assumption as well. *Assuming* that the filesystem snapshot is
> consistent. There are a bunch of solutions that don't do consistent
> snapshots between different partitions, so if your WAL or one tablespace is
> on a different partition, you'll get corruption anyway... (seen this in
> Big Commercial Database, so that's not a pg problem)
>
Agreed. That's why I made it a point to mention that all of your
tablespaces should be on the same file system... In hindsight, I should
have also stated that your WAL logs should be on the same file system as
well...
--
Chander Ganesan
Open Technology Group, Inc.
One Copley Parkway, Suite 210
Morrisville, NC 27560
919-463-0999/877-258-8987
http://www.otg-nc.com
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To: pgsql-general@postgresql.org
Cc: chander@otg-nc.com, magnus@hagander.net, simon@2ndquadrant.com, phillip.smith@weatherbeeta.com.au, carlucci@cae.com, pgsql-admin@postgresql.org, carlucci@cae.ca
Subject: Re: [GENERAL] Backup
In-Reply-To: <47A1E2F6.7060108@otg-nc.com>
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